苎麻纤维闪爆处理及性能研究

利用闪爆法对苎麻纤维进行脱胶处理,并测试苎麻纤维闪爆处理前后的化学成分、结晶度、力学性能、吸湿性、保水性及热学性能,分析闪爆处理分离苎麻纤维的可行性。结果表明,闪爆处理可以大幅降低苎麻纤维内部的木质素与胶质等,并能提高苎麻纤维的纤维素含量、结晶度及热学性能,但受闪爆机械冲击影响,苎麻纤维的力学性能、吸湿性与保水性有所下降。此外,在相同保压时间条件下,分次闪爆的效果优于一次闪爆。该研究证明可以利用分次闪爆法去除苎麻纤维内部的木质素、胶质等以及提高纤维分离度,为苎麻纤维的开发利用提供了一种洁净工艺。     

人工神经网络在纤维增强复合材料力学性能研究中的应用

介绍了人工神经网络的基本工作原理和常用的几种模型,讨论了将人工神经网络用于纤维增强复合材料力学性能研究的一般方法。     

苎麻纤维的碱性复合生物酶脱胶工艺研究

通过预处理、复合酶处理和碱精炼工艺对苎麻纤维进行脱胶处理,得到优化的碱性复合生物酶脱胶工艺:将乙二胺四乙酸二钠水溶液预处理的苎麻纤维通过果胶酶(40 g/L)和漆酶(10 g/L)的复合酶在52℃处理3 h;随后,在100℃通过NaOH水溶液(10 g/L)继续处理3 h.通过该工艺处理后的苎麻纤维残胶率为4.8％,断...     

纤维复合材料在医学的应用

本文探讨了纤维复合材料在医学应用中的要求,分析了骨粘合剂人工骨、骨夹板等几个实际应用,最后简要介绍了一个实例的设计方法。     

偶联改性苎麻环氧树脂复合材料性能研究

采用硅烷偶联剂KH550和钛酸酯偶联荆NDZ201处理苎麻纤维,分析了处理前后苎麻纤维的回潮率变化,以及苎麻增强环氧树脂复合材料在改性前后的力学性能变化.结果表明随着偶联剂浓度的增加,苎麻纤维回潮率降低,并且复合材料的力学性能得到不同程度的提高.     

苎麻织物复合材料抗光变色及力学性能表征

针对苎麻织物复合材料在实际工作环境下易变色和受到复杂应力的问题,对3种树脂基体复合材料的抗光变色性能、双轴向载荷下的力学性能进行研究,并用数字散斑相关方法对其应变场进行表征.结果表明:双轴向载荷下水性环氧树脂板和异氰酸酯板表现出正交异性和弹塑性,酚醛树脂板表现出线性和双向同时脆性断裂;双轴向载荷差异与材料正交异性有关;...     

剑麻纤维/聚丙烯复合材料物理力学性能的研究

研究了剑麻纤维(SF)的预处理方法、长度和含量对剑麻纤维/聚丙烯(SF/PP)复合材料物理力学性能的影响,采用扫描电子显微镜(SEM)对复合材料的冲击断面进行微观结构分析.实验结果表明:SF经过碱处理和蒸汽爆破处理后,复合材料的冲击强度分别提高了70%、76%;当SF的长度为5～8 mm、含量为20%时复合材料的冲击强度达到最大为21.99 kJ/m2;SF含量为50%时弯曲强度、弯曲弹性模量与纯PP相比提高了27.5%、41.1%;熔体流动速率和吸水率随SF含量的增加变化明显.     

苎麻织物与玻璃织物的力学性能研究

本文主要通过织物拉伸断裂强力试验,结合织物本身的结构,分析影响其力学性能的因素,对苎麻布与玻璃纤维布的力学性能做了研究。试验结果表明,纱线支数和织物单位面积克重(厚度)是分别影响苎麻布、玻璃纤维布拉伸强度的最主要因素。玻璃纤维布的比强度经纬向平均值为45.387MPa/(g/cm3),接近于苎麻布的33.226MPa/(g/cm3),苎麻布在比力学性能方面与玻璃纤维布相当。     

剥制苎麻的高效煮练脱胶

剥制苎麻不用硫酸浸解,而用碱性水浴浸解,在煮练脱胶时,采用高效煮练剂,在常压下煮练时间缩短至40min,省去了漂白工序,所得精干麻的残胶率很低(平均ω=1.76×10~(-2)),单纤维的支数高(平均2031Nm,即4.92dtex),强度很高(平均9.68cN/dtex),白度也较高(平均65.8),达到日本东洋纤维公司的水平,精干麻符合纺高支纱的要求,为苎麻脱胶的机械化和连续化提供了一条可靠的技术路线。     

废弃苎麻纤维吸声复合材料的制备及其性能分析

以废弃苎麻纤维为增强材料,乙烯-醋酸乙烯酯共聚物为基体材料,使用热压工艺制备废弃苎麻纤维/乙烯-醋酸乙烯酯共聚物吸声阻燃复合材料。设计实验以吸声系数为评测标准,测得最佳的工艺参数为:热压温度125℃,热压压力8 MPa、热压时间25 min、苎麻纤维质量分数45%、材料密度0.204 g/cm~3、材料厚度25 mm、后空气层厚度10 mm。最优工艺条件下,材料的平均吸声系数为0.48,降噪系数为0.50,最高吸声系数可达0.9以上,为废弃苎麻纤维的回收利用提供了新的利用途径,可将其制造成新型吸声材料来治理噪声污染。     

Mechanical properties of bamboo fiber bundle-reinforced bamboo powder composite materials

European Journal of Wood and Wood Products - This paper reports the mechanical properties of bamboo fiber bundle-reinforced bamboo powder composite materials. Bamboo fiber bundle-reinforced bamboo...     

Degumming of ramie bast fibers by Ca2+-activated composite enzyme

In recent years, special attention has been paid to the application of biotechnology in the textile industry. In this study, composite enzyme (contained pectatelyase/hemicellulase/laccase) was employed to degum the ramie bast successfully. Interestingly, the activities of enzymes were enhanced by promotion of Ca²⁺ activated remarkably. The test of degummed ramie fiber performance demonstrated that fiber fineness, breaking strength, whiteness, and residual gum of fibers have greatly improved. Further, the structure and morphous of the fibers before and after degumming was examined and analyzed. The results showed that the gum, hemicellulose, and lignin were removed effectively and treated fibers had the typical cellulose I structure suitable for direct textile and other applications. These outcomes suggested that Ca²⁺-activated composite enzyme could degum the gum of ramie bast effectively, which provided a method to improve the quality of ramie fibers and a theoretical basis for flax degumming technique on an environmentally-friendly basis.     

Influence of low-temperature plasma treatment on properties of ramie fibers

In this study, ramie fibers were treated under various low-temperature plasma conditions such as different output powers (100, 150, 200, 250, and 300 W) and irradiation times (1, 1.5, 2, 2.5, and 3 min). The effects on fiber surface morphology, contact angle, friction and tensile properties were investigated. The results showed that properties of ramie fibers changed significantly after low-temperature plasma treatment. Compared with the untreated fibers, surface free energy increased 117.0 and 122.9%, friction coefficient improved 10.7 and 13.4% after 1 min-300 W and 3 min-100 W treatment. However, with the higher output power and the prolonged treatment time, low-temperature plasma treatment may cause damage to the tensile property of ramie fiber. Scanning electron microscopy showed that pectin and impurities covering of fibers were removed after low-temperature plasma treatment and alkali treatment, and the surface of ramie fiber was etched by low-temperature plasma treatment. Based on the analysis of experimental results, three groups (1 min-100 W, 2 min-150 W, and 3 min-200 W) were chosen as the following treatment process and compared with alkali treatment. It was found that properties of ramie fibers had more significant change after low-temperature plasma treatment.     

莲纤维的力学性能

为开发莲纤维织物提供理论依据,初步研究了莲纤维的力学性能,主要包括单次拉伸性能、定负荷拉伸弹性和摩擦性能。结果表明：莲纤维的初始模量为146.81cN/dtex,比棉、羊毛和蚕丝的初始模量高,与苎麻接近;莲纤维的断裂强度为3.44 cN/dtex,要优于棉、羊毛、蚕丝,仅次于苎麻;而断裂伸长率为2.25%,与苎麻相近,比棉、羊毛和蚕丝小。在小应力下,莲纤维的弹性较好;莲纤维的静、动摩擦因数分别为0.5541、0.3203,属于手感较涩糙的纤维。     

苎麻纤维机械物理性能的主成分及聚类分析

应用SAS统计软件,对107个苎麻品种的头麻纤维线密度、断裂强力等11个指标进行主成分分析,按累计贡献率大于或等于90%选出前3个主成分。在此基础上对这107个苎麻品种进行聚类分析,将其聚为4类,类群Ⅰ和类群Ⅳ综合物理性能中等,类群Ⅱ综合物理性能较好,类群Ⅲ综合物理性能较差。     

Mechanical and barrier properties of composite films based on rice flour and cellulose fibers

Rice flour is a low-cost starchy material, produced from rice that is broken during processing. Rice flour-based films have promising application on food packaging, because of their environmental appeal and low cost. Nevertheless, their mechanical and moisture barrier properties should be improved. The aim of this study was to develop biodegradable films based on rice flour and enhance their properties by reinforcing them with cellulose fibers. In this way, rice flour films with and without fibers were prepared by casting, with glycerol or sorbitol as plasticizer. Their physicochemical, microscopic and mechanical properties were studied. SEM analysis of films revealed compact structures. Films prepared with fibers presented lower water vapor permeabilities if compared with films without fibers. Films containing sorbitol were less permeable to water and more rigid. The incorporation of fibers reinforced mechanically the flour-based films, which presented higher tensile strength, but did not influence their deformation capacity. Therefore, preparing biodegradable films from rice flour is a new alternative of using this raw material. The use of cellulose fibers as reinforcing agent is a viable alternative to improve the properties of rice flour-based films, because they are biodegradable and available at low cost.     

蒽醌助剂对乙二醇溶剂脱胶苎麻纤维性能的影响

为解决苎麻在乙二醇有机溶剂脱胶中纤维易被氧化而导致性能下降的问题,在乙二醇溶剂中添加助剂蒽醌对苎麻进行脱胶,并对蒽醌不同添加量下制得的纤维进行结构和性能表征。结果表明:纤维中半纤维素含量随蒽醌添加量的增加而升高,纤维的聚合度、结晶度、物理力学性能先升高后降低,纤维的残胶率和线密度先降低后升高;当蒽醌质量分数为0.3% 时,这些性能均达到最佳值,此时纤维的聚合度、结晶度、制成率、断裂强度、断裂伸长率、断裂功比不加蒽醌时分别提高了7.32%、20.53%、1.46%、9.55%、6.89%、33.33%,纤维的残胶率、线密度比不加蒽醌时分别降低了17.91%、7.24%。     

Study on length distribution of ramie fibers

The extra-long length of ramie fibers and the high variation in fiber length has a negative impact on the spinning processes. In order to better study the feature of ramie fiber length, in this research, the probability density function of the mixture model applied in the characterization of cotton fiber length was used to fit the ramie fiber length distribution tested by the Y131 wool fiber comb stapling sorter. Furthermore, the generation of ramie fiber length distribution with the commonly used ramie fiber length parameters was also studied, and it was concluded that ramie fiber length distribution could be generated by the corresponding tested fiber length parameters.     

不同成型工艺棕叶纤维/PHBV复合材料的力学性能

研究了精细化棕叶散纤维/PHBV热压复合、棕叶纤维针刺非织造布/PHBV热压复合、棕叶纤维粉末/PHBV共混复合材料的力学性能.以拉伸强度、冲击强度、弹性模量、断裂伸长率为指标探讨了PHBV质量分数、热压压强的影响,并通过SEM观测了复合材料的拉伸断面形貌.结果表明:当PHBV质量分数相同时,棕叶纤维针刺非织造布/PH...